The invention relates to a backpack or a knapsack.
Backpacks or knapsacks are containers, usually made of fabric, that have straps and other means for permitting a user to carry the container on his or her back. A backpack has a pair of shoulder straps, and perhaps a hip belt (together, the shoulder straps and the hip belt are known as the xe2x80x9charnessxe2x80x9d) on its body-contact side for attachment to the user""s shoulders and hips, respectively, to support and secure the backpack in place against the user""s back. The use of a tumpline secured to the user""s forehead in place of shoulder straps and hip belt is of course well known, particularly in the Kingdom of Nepal, but the discussion of backpacks in this section of the specification will assume that shoulder straps and perhaps a hip belt are provided.
A user that carries heavy loads in a backpack attached to his or her back will expend considerable energy even when traveling over level terrain, in addition to suffering aches and pains. One way to reduce the exertion and pain of carrying heavy loads, of course, is to reduce the weight of the load carried. Reducing the weight carried is often more easily advocated than accomplished. The xe2x80x9cRay wayxe2x80x9d advocated in recent years by ultra long distance hiker Ray Jardine is a disciplined approach to the reduction of pack weight evolved in the context of long distance backpacking, such as for through-hikes of the Pacific Crest Trail. See generally Ray Jardine, The Pacific Crest Trail Hiker""s Handbook (1996).
Nevertheless, a reduction in the load to be carried is not always possible. For example, professional photographers may have to carry a minimum amount of photographic equipment, in addition to personal gear, in order to perform an assignment. The necessary lenses, camera bodies, tripods, and the like will often amount to a considerable weight.
Climbers often must carry heavy technical climbing gear in addition to their survival gear and rations. In addition, big wall climbers must carry large (and thus heavy) quantities of water to the base of their climbs.
The adults in families with small children may need to carry a considerable amount of gear for both themselves and the children when traveling or hiking.
Hikers and other travelers may be unwilling to make the sacrifices in creature comforts needed to travel with a light load. Furthermore, persons planning to hike long distances without resupply will need to carry a large amount of food. A large and heavy quantity of water will be carried if crossing terrain lacking water sources, such as in deserts.
Thus, one solution to reducing the exertion and pain of carrying a heavy load is to provide a container for the load with wheels so that the container can be pushed or pulled across the surface of the ground (by surface of the xe2x80x9cgroundxe2x80x9d is meant any natural or man-made surface) while the wheels support the weight of the container. This mode of transporting a container will require less exertion (and pain) because the user does not have to support the dead weight of the backpack and its contents.
Of course, the user can employ this mode of transport only when the nature of the ground permits. Rough and irregular surfaces could make supporting and rolling a container on its wheels inconvenient because the irregularities will resist the movement of the wheels and the container will have to be lifted over these irregularities. Some surfaces may be so rough and steep that the user will have to employ his or her hands in order to progress up, down or laterally, such as in climbing at Class 3 (Yosemite Decimal System) and above, and will not be able to spare a hand to push or pull the container. Furthermore, the user may have to employ his or her hands to carry handbags or other containers and will not have a free hand to push or pull the wheeled container.
In such situations, the user must carry the container, preferably on his or her back. Providing wheels to a backpack therefore permits the user to choose the mode of transport according to the situation at hand.
Wheeled backpacks have been known for some time. For example, Talbot, U.S. Pat. No. 2,401,986, describes a xe2x80x9cpack cart of a type adapted to be used as a cart for wheeling a pack over the ground or as a pack frame for carrying a pack on the back.xe2x80x9d Other examples of backpacks with wheels are H. R. Strand, U.S. Pat. No. 3,550,997 for a xe2x80x9cBackpack Trundling Assembly,xe2x80x9d Cesari, U.S. Pat. No. 5,022,574 for a xe2x80x9cUtility Bag,xe2x80x9d Mitomi, et al., U.S. Pat. No. 5,588,569 for a xe2x80x9cCarrier Bag,xe2x80x9d Arbel, U.S. Pat. No. 5,634,576 for a xe2x80x9cKnapsack,xe2x80x9d McDermott, U.S. Pat. No. 5,743,447 for a xe2x80x9cPortable Variable Capacity Backpack,xe2x80x9d and Wulf, et al., U.S. Pat. No. 5,749,503 for a xe2x80x9cConvertible Luggage System.xe2x80x9d Typically, such backpacks have at least two wheels, a handle at the top for pulling or pushing the backpack when it is rolling on the wheels, and some form of rigidity due to an external frame, internal stiffening members or a hard shell construction.
A useful development of late is shown in Wulf, et al., which has a rigid handle that can be deployed from the top of the backpack or luggage container but can also be stored internally in a retracted position.
The known wheeled backpacks have wheels that are xe2x80x9cfixed,xe2x80x9d meaning that the wheels are not designed to be removed by the user. Furthermore, these wheels are usually placed at the bottom of the body-contact side of the backpack, as in Wulf, et al., Arbel, Mitomi, et al., and McDermott. This has the disadvantage of placing of placing the wheels adjacent to the user""s back when the backpack is carried on the user""s back. For this reason, Wulf, et al. provide a cover to be wrapped over the wheels to protect the user""s back from the xe2x80x9cfilth that accumulates on the wheels.xe2x80x9d Another disadvantage is that the harness (shoulder straps and possibly a hip belt) is exposed to or dragged on the ground when the backpack is pulled or pushed in its wheel-supported or rolling mode. Wulf, et al. therefore secure the cover previously mentioned over the shoulder straps when the backpack or luggage container is in the rolling mode.
Strand and Talbott address these problems by providing wheels on complicated swiveling frames that deploy the wheels into a rolling or ground-contacting position below the backpack or in front of the body-contact side, respectively. The swiveling frames position the wheels adjacent the non body-contact side when the backpack is to be carried on the user""s back. Tetzlaff, German Patentschrift 120005, locates the wheels at the top of the non body-contact side.
Another solution to the problems noted above is to place the wheels at the base of the non body-contact side of the backpack, as in Song, U.S. Pat. No. 5,676,286 for a xe2x80x9cWheeled Knapsack.xe2x80x9d The wheels therefore are never adjacent to the user""s back when the user carries Song""s wheeled knapsack or backpack on his or her back. No complicated and heavy swiveling frames for the wheels are needed. Furthermore, the harness or shoulder straps (and hip belt, if one is provided) is positioned away from the ground when the backpack is pulled across the surface of the ground on its wheels.
Song, however, does not explain how the xe2x80x9cbag portionxe2x80x9d or body of her knapsack is to be provided with the rigidity necessary for her wheeled knapsack to be pulled across the surface of the ground in a rolling or wheel-supported mode without deformation of the bag and contact of parts of the bag, other than the wheels, with the ground. Song also does not show how the user will access the compartment inside her wheeled knapsack.
Backpacks traditionally have openings at their tops (top-loaders such as the Great Pacific Iron Works"" Creagh Dubh climbing pack and The North Face""s Liberty backpack) or on the non body-contacting side (panel loaders such as The North Face""s Ruthsac backpack and Big Shot backpack) or a hybrid or combination of the two (such as Lowe Alpine Systems"" Contour IV backpack) to provide access to the contents of the main or interior compartment or compartments of the backpack. See generally Kristin Hostetter, Packs, Backpacker Magazine 2000 Gear Guide, March 2000, at 14. Such backpacks must be placed on their bottoms or on their body-contacting sides in order for the user to access the contents of the main or interior compartment(s) of the backpacks. A panel-loading backpack provides excellent access to the interior compartment(s) of the backpack but at the requirement of placing the pack on its body-contacting side. This will require putting the harness on the ground or other surface and thereby exposing it to dirt and abrasion.
Song""s backpack will have the body-contacting side upwards when the backpack is supported on its wheels. This position will render access to the inner compartment difficult if her backpack is a panel-loader of the known kind unless the Song backpack is tipped onto its body-contacting side, which will have the negative effects mentioned above.
Furthermore, Song provides only a flexible U-shaped handle or a strap to be grabbed and pulled by the user when her wheeled knapsack is in its rolling mode. A flexible handle does not provide sufficient control of a wheeled backpack in its rolling mode and cannot be used to push the backpack when in that mode. Song also teaches the use of xe2x80x9cfixedxe2x80x9d wheels, which means that the size of the wheels must be small enough to not be in the way or inconvenient when her wheeled knapsack is carried on the back or otherwise not in its rolling mode of use. Smaller wheels, however, are difficult to use on irregular surfaces.
A need exists, therefore, for a backpack that can be equipped with wheels at its base adjacent its non body-contact side for transport in a rolling mode on the surface of the ground and has the necessary structural rigidity, an opening into its inner compartment that will not require the harness to be placed on the ground when the user accesses the inner compartment, a handle for pushing as well as pulling, and wheels suitable for use on rough ground.
The invention provides a backpack with features especially useful for a backpack equipped with wheels.
A preferred embodiment of a backpack according to the invention comprises a bag portion having a body-contact side, a non-body contact side, two side panels, a top, and a base, the body-contact side and the non body-contact side facing each other and being joined to the base, the side panels, and the top so as to define a compartment; a pair of shoulder straps provided on the body-contact side of the bag portion and adapted to be hung from the user""s shoulders; a U-shaped opening defined in the bag portion adjacent and parallel to the body-contact side; a zipper having complementary halves attached on either side of the opening, the haves of the zipper having at least one slider for reversibly separating the halves of the zipper for permitting access to the compartment and reversibly attaching the halves of the zipper for securing the opening from entry from the exterior of the backpack; a frame assembly extending along and attached to the non body-contact side, the frame assembly comprising a bottom portion and a top portion; at least one wheel assembly attached to the bottom portion of the frame assembly, at least a portion of the wheel assembly extending out from the bag portion whereby the wheel assembly can support a substantial part of the weight of the backpack when the bag portion is substantially above the wheel assembly and the wheel assembly is in contact with a surface; and a handle attached to a first end of at least one member made of a rigid material and mounted to the frame so that the member can slide between an extended position above the top portion of the frame assembly in which the user can grasp the handle and pull or push the bag portion of the backpack across a surface when the weight of the bag portion is substantially resting on the at least one wheel assembly and a retracted position in which the handle is adjacent the top portion of the frame assembly.
Another preferred embodiment of the backpack according to the invention comprises a bag portion having a body-contact side, a non-body contact side, two side panels, a top, and a base, the body-contact side and the non body-contact side facing each other and being joined to the base, the side panels, and the top so as to define a compartment; a pair of shoulder straps provided on the body-contact side of the bag portion and adapted to be hung from the user""s shoulders; a U-shaped opening defined in the bag portion adjacent and parallel to the body-contact side; a zipper having complementary halves attached on either side of the opening, the haves of the zipper having at least one slider for reversibly separating the halves of the zipper for permitting access to the compartment and reversibly attaching the halves of the zipper for securing the opening from entry from the exterior of the backpack; and at least one side strap joining the body-contact side to one of the side panels and the non body-contact side whereby a substantial part of the weight of the backpack is transferred to the body-contact side when the backpack is mounted on the user""s back and thereby reducing the tension on the zipper when the opening to the compartment is closed.
This preferred embodiment of a backpack according to the invention may further comprise a top strap disposed across the top, the top strap comprising a first end attached to the body contact side, a second end attached to one of the top and the non body-contact side, and intermediate releasable fastening means whereby the top strap can be connected across and above the opening in order to reduce the tension on the zipper when the opening to the compartment is closed and the backpack is mounted on the user""s back.
Yet another preferred embodiment of a backpack according to the invention comprises a body portion defining a compartment, the body portion comprising a body-contact side, the body-contact side comprising at least one stiffening member and a pair of shoulder straps provided on the body-contact side adapted to be hung from the user""s shoulders; a U-shaped opening defined in the bag portion adjacent and parallel to the body-contact side; a zipper having two ends and complementary halves attached on either side of the opening, the haves of the zipper having at least one slider for reversibly separating the halves of the zipper between the two ends for permitting access to the compartment and reversibly attaching the halves of the zipper for securing the opening from entry from the exterior of the body portion; and the opening curves at either end of the zipper so that the ends of the zipper are substantially in line and directed toward each other, whereby the zipper is not twisted when the body-contact side is rotated away from the remainder of the body portion in order to expose the compartment to access from the exterior.
A further preferred embodiment of a pack according to the invention comprises a bag portion having front and back sides and a base, the front and back sides facing each other and being joined to the base; a frame assembly attached to the bag portion and having an upper end and a lower end, the lower end being adjacent to the base of the bag portion; two wheel assemblies detachably connected to the lower end of the frame assembly, the two wheel assemblies when connected to the frame assembly being positioned apart from each other and having the same axis, the two wheel assemblies further being capable of being attached to and detached from the frame assembly by the user; and a handle attached to the frame assembly for pulling the backpack when the wheel assemblies support the backpack on the ground.
Still another preferred embodiment of a backpack according to the invention comprises a bag portion having a body-contact side, a non body-contact side, and a base, the body-contact side and the non body-contact side facing each other and being joined to the base; a frame attached to one of the body-contact side and the non body-contact side; a pair of shoulder straps provided on the body-contact side of the bag portion and adapted to be hung from the user""s shoulders; two wheel assemblies connected to the frame and positioned apart from each other and having the same axis; and a handle attached to the bag portion for pulling the backpack on the ground, the handle having at least one extensible member slidably attached to the frame and grip portion for being grasped by the user""s hand, the extensible member having an extended position away from the base so that the handle can be readily grasped by the user for towing or pushing the backpack and a contracted position adjacent the frame, the movement of the extensible member between the extended position and the contracted position being accomplished at least in part by the user exerting pressure on the grip portion away from the bag portion or towards the bag portion, repectively.
An object of the invention is to provide a backpack with an opening adjacent the body-contact side.
A further object of the invention is to provide a system for substantially reducing the tension on the zipper or other apparatus closing an opening adjacent the body-contact side of a backpack when the user carries the backpack on his or her back.
Still another object is to provide a backpack with wheel assemblies.
A related and further object is to provide a backpack with wheel assemblies that permit greater stability and cross-country mobility than known packs when in the rolling or wheel-supported mode of transport.
Another object of the invention is to provide a backpack with removable wheels at the base of the non body-contact side of the backpack.
Yet another object of the invention is to provide a backpack with wheels at the base of the non body-contact side of the backpack and an internal frame for stiffening.
A related and further object is to provide a backpack with wheels at the base of the non body-contact side of the backpack and a handle system that is rigid when deployed so that the backpack may be pushed with the handle system when it is supported by its wheels in a rolling mode.
A yet further object is to provide a backpack with wheels at the base of the non body-contact side of the backpack and an opening into an interior compartment adjacent the body-contact side of the backpack.